A lead frame can function as a chip carrier for an integrated circuit, and can also establish an electrical connection between the chip and outside circuitry. A lead frame can be in different structures corresponding to different package structures (e.g., flip chip package). Most of the conventional lead frames have a regular geometric shape to facilitate production. Conventionally, bond wires may be applied to connect the semiconductor chip to the lead frame. However, in flip chip semiconductor packaging, a plurality of solder bumps can be used to electrically connect the chip to the substrate or the lead frame. This flip chip semiconductor package structure may not only greatly decrease the package size because the size of the substrate can be close to the semiconductor chip size, but also can eliminate parasitic resistances on the bond wires to lower the impedances and improve signal transmission efficiency.